php - facebook api file upload getting 324 error -

i'm using php facebook api 4.0. i'm using below code post photo on timeline.

facebooksession::setdefaultapplication($app_id, $app_sc);  $helper = new facebookredirectloginhelper($url_page); $loginurl = $helper->getloginurl(); $session = new facebooksession($access_token); facebooksession::enableappsecretproof(false);   if($session) {   try {     $response = (new facebookrequest(       $session, 'post', '/me/photos', array(         'source' => '@' . realpath('1.jpg'),         'message' => 'message'       )     ))->execute()->getgraphobject();     // if you're not using php 5.5 or later, change file reference to:     // 'source' => '@/path/to/file.name'     echo "posted id: " . $response->getproperty('id');   } catch(facebookrequestexception $e) {     echo "exception occured, code: " . $e->getcode();     echo " message: " . $e->getmessage();   } } 

but i'm getting exception occured, code: 324 message: (#324) requires upload file error. think 1 thing that, fileupload support should set on. don't know should turn on.